Both Nikon L31 and Kodak Z5120 have 16.0 MP resolution sensors but Nikon L31's sensor is 1/2.3' (6.17 x 4.55 mm ) and Kodak Z5120's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Kodak Z5120's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Nikon L31.
Below you can see the L31 and Z5120 sensor size comparison.
Nikon L31 and Kodak Z5120 have sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Kodak Z5120 has 40% larger pixel area (2.48µm2 vs 1.76µm2) compared to Nikon L31, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.